2-arylmethyliminopyrazines pyrazines, compositions and method of combating undesirable plant growth and of regulating plant growth

ABSTRACT

2-Arylmethyliminopyrazines of the formula I ##STR1## in which R 1  is SR 2  ; OR 2  ; O--CHR 10  R 2  ; N(R 3 )(CHR 10  R 4 ); N(R 11 )(CHR 10  R 4 ) or NR 3  R 4  ; R 2  is C 1  -C 10  - alkyl which is unsubstituted or substituted by hydroxyl, mercapto, C 1  -C 4  -alkoxycarbonyl, mercaptoalkoxy, C 1  -C 4  -alkoxy, C 1  -C 4  -alkylcarbonyl, mono- or di-C 1  -C 4  -alkylamino, C 1  -C 4  -haloalkoxy, tri-(C 1  -C 4  -alkoxy)-silyl, cyano, nitro or phenyl; C 1  -C 4  -haloalkyl; C 3  -C 8  -alkenyl; (3-methyl-oxetan-3-yl)methyl; C 3  -C 8  -alkynyl; or a radical from the group comprising phenyl, benzyl, C 3  -C 7  -cycloalkyl, furanyl or furfuryl which is unsubstituted or mono-, di- or trisubstituted by identical or different substituents from the group comprising halogen, C 1  -C 4  -alkyl, C 1  -C 4  -alkylcarbonyl, nitro, C 1  -C 4  -alkoxy and C 1  -C 4  -haloalkyl; R 3  and R 4  independently of one another are hydrogen; a phenyl or benzyl radical which is unsubstituted or mono-, di-, tri- or tetrasubstituted by identical or different substituents from the group comprising halogen, C 1  -C 4  -alkyl, C 1  -C 4  -alkylcarbonyl, nitro, C 1  -C 4  -alkoxy, C 1  -C 4  -haloalkyl, C 1  -C 4  -alkylthio and C 1  -C 4  -haloalkylthio; C 1  -C 8  -alkyl; or C 3  -C 6  -cycloalkyl; or R 3  and R 4 , together with the nitrogen atom, form a saturated 5- or 6-membered heterocyclic ring which contains up to two heteroatoms from the group comprising N, O and S and can be mono- or disubstituted by C 1  -C 4  -allkyl; R 5  is hydrogen; halogen; C 1  -C 8  -alkyl; C 1  -C 4  -alkoxy; C 1  -C 4  -haloalkyl; nitro; cyano; C 1  -C 4  -haloalkoxy; phenylthio; di-C 1  -C 4  -alkylamino; phenyl; or is phenoxy which is unsubstituted or substituted by the radicals R 8  and R 9  ; and R 6 , R 7 , R 8  and R 9  independently of one another are hydrogen; halogen; C 1  -C 8  -alkyl; C 1  -C 4  -haloalkyl; C 1  -C 4  -alkoxy; C 1  -C 4  -haloalkoxy; nitro; cyano; or di-C 1  -C 4  -alkylamino; and R 10  and R 11  independently of one another are C 1  -C 4  -alkyl; and salts of compounds of the formula I with acids and bases, process for their preparation and herbicidal or plant growth-regulating compositions containing compounds of the formula I.

The invention relates to new pyrazines, compositions and a method ofcombating undesirable plant growth and of regulating plant growth.

Fungicidally active 5-arylmethyliminopyrimidines have been disclosed inEuropean Patent Application EP-A No. 175,651. Surprisingly, it has nowbeen found that 3-arylmethyliminopyrazines of the general formula I havea herbicidal action against numerous weeds and grasses.

2-Arylmethyliminopyrazines were disclosed in our European PatentApplication No. 0,207,000, published on 30.12.1986, as fungicidalagrochemical active substances.

The invention thus relates to pyrazines of the formula I ##STR2## inwhich R₁ is SR₂ ; OR₂ ; O--CHR₁₀ R₂ ; N(R₃)(CHR₁₀ R₄); N(R₁₁)(CHR₁₀ R₄)or NR₃ R₄ ; R₂ is C₁ -C₁₀ -alkyl which is unsubstituted or substitutedby hydroxyl, mercapto, C₁ -C₄ -alkoxycarbonyl, mercaptoalkoxy, C₁ -C₄-alkoxy, C₁ -C₄ -alkylcarbonyl, mono- or di-C₁ C₄ -alkylamino, C₁ -C₄-haloalkoxy, tri-(C₁ -C₄ -alkoxy)-silyl, cyano, nitro or phenyl; C₁ -C₄-haloalkyl; C₃ -C₈ -alkenyl; (3-methyl-oxetan-3-yl)methyl; C₃ -C₈-alkynyl; or a radical from the group comprising phenyl, benzyl, C₃ -C₇-cycloalkyl, furanyl or furfuryl which is unsubstituted or mono-, di- ortrisubstituted by identical or different substituents from the groupcomprising halogen, C₁ -C₄ -alkyl, C₁ -C₄ -alkylcarbonyl, nitro, C₁ -C₄-alkoxy and C₁ -C₄ -haloalkyl; R₃ and R₄ independently of one anotherare hydrogen; a phenyl or benzyl radical which is unsubstituted ormono-, di-, tri- or tetrasubstituted by identical or differentsubstituents from the group comprising halogen, C₁ -C₄ -alkyl, C₁ -C₄-alkylcarbonyl, nitro, C₁ -C₄ -alkoxy, C₁ -C₄ -haloalkyl, C₁ -C₄-alkylthio and C₁ -C₄ -haloalkylthio; C₁ -C₈ -alkyl; or C₃ -C₆-cycloalkyl; or R₃ and R₄, together with the nitrogen atom, form asaturated 5- or 6-membered heterocyclic ring which contains up to twoheteroatoms from the group comprising N, O and S and can be mono- ordisubstituted by C₁ -C₄ -alkyl; R₅ is hydrogen; halogen; C₁ -C₈ -alkyl;C₁ -C₄ -alkoxy; C₁ -C₄ -haloalkyl; nitro; cyano; C₁ -C₄ -haloalkoxy;phenylthio; di-C₁ -C₄ -alkylamino; phenyl; or is phenoxy which isunsubstituted or substituted by the radicals R₈ and R₉ ; and R₆, R₇, R₈and R₉ independently of one another are hydrogen; halogen; C₁ -C₈-alkyl; C₁ -C₄ -haloalkyl; C₁ -C₄ -alkoxy; C₁ -C₄ -haloalkyloxy; nitro;cyano; or diC₁ -C₄ -alkylamino; and R₁₀ and R₁₁ independently of oneanother are C₁ -C₄ -alkyl; and salts of the compounds of the formula Iwith acids and bases.

In the above definition, the generic terms given include, for example,the following specific individual substituents, this list notrepresenting a limitation to the invention:

Alkyl includes straight-chain or branched C₁ -C₁₀ -alkyl, such asmethyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl,isobutyl, the isomeric pentyl radicals, for example tert.-pentyl(1,1-dimethylpropyl), and isopentyl (1-ethylpropyl), and the isomerichexyl, heptyl, octyl, nonyl and decyl radicals. C₁ -C₄ -Alkyl radicalsare preferred.

Halogen is fluorine, chlorine, bromine or iodine.

Haloalkyl is alkyl according to the particular range defined which iscompletely or partly substituted by identical or different halogenatoms, for example 2,2,2-trifluoroethyl,1,1,1,3,3,3-hexafluoroprop-2-yl, trifluoromethyl or difluoromethyl.

C₃ -C₈ -Alkenyl includes both the structurally isomeric and thecis/transisomeric propenyl, butenyl, pentenyl, hexenyl, heptenyl andoctynyl radicals. C₃ -C₅ -Alkenyl, for example allyl, is preferred.

C₃ -C₈ -Alkynyl includes the isomeric propynyl, butynyl, pentynyl,hexynyl, heptynyl and octynyl radicals. C₃ -C₅ -Alkynyl, for examplepropargyl or 2-methyl-but-3-yn-2-yl, is preferred.

Alkoxycarbonyl radicals are, inter alia, methoxycarbonyl, ethoxycarbonyland the isomeric propoxycarbonyl and butoxycarbonyl radicals.

Alkoxy in the context of the particular range defined for the isomericalkoxy radicals is primarily methoxy or ethoxy.

Alkyl substituted by mercaptoalkoxy radicals is, for example,2-(2-mercaptoethoxy)-ethyl.

Haloalkoxy and haloalkylthio in the context of the particular rangedefined are the isomeric alkyl radicals which are mono- orpolysubstituted by halogen, for example trifluoromethoxy,2,2,2-trifluoroethoxy, trifluoromethylthio or2,2,3,3,3-pentafluoropropoxy.

Alkoxyalkyl radicals are, inter alia: 2-ethoxyethyl, 2-methoxyethyl,3-methoxypropyl, 2-methoxy-1-methylethyl and methoxymethyl.

C₃ -C₆ -Cycloalkyl is cyclopropyl, cyclobutyl, cyclopentyl andcyclohexyl.

Saturated 5- or 6-membered heterocyclic radicals with up to twoheteroatoms from the group comprising N, O and S are: pyrrolidinyl,piperidinyl, piperazinyl, morpholinyl, thiomorpholinyl andthiazolidinyl. The heterocyclic radicals can be mono- or disubstitutedby C₁ -C₄ -alkyl, for example the 2,6-dimethylmorpholin-4-yl radical orthe 3-ethylpiperidinyl radical.

Tri-C₁ -C₄ -alkoxysilyl is a group which is trisubstituted by identicalor different alkoxy radicals, such as triethoxysilyl,diethoxy-tert.-butoxy-silyl or trimeth- oxy-silyl.

Di-C₁ -C₄ -alkylamino is a group which is substituted by identical ordifferent alkyl radicals, such as dimethylamino, diethylamino ormethylethylamino.

In the other substituents, which are composed of several basic elements,the component elements can be freely chosen within the range defined andare as defined above.

Compounds of the formula I in which R₁ is SR₂ ; OR₂ ; O--CHR₁₀ R₂ ;N(R₃)(CHR₁₀ R₄); N(R₁₁)(CHR₁₀ R₄) or NR₃ R₄ ; R₂ is C₁ -C₆ -alkyl whichis unsubstituted or substituted by hydroxyl, mercapto, methoxycarbonyl,phenyl, di-C₁ -C₂ -alkylamino, cyano, nitro, C₁ -C₂ -alkoxy, acetyl ortri-(C₁ -C₄ -alkoxy)-silyl; C₇ -C₁₀ -alkyl;(3-methyl-oxetan-3-yl)methyl; C₁ -C₃ -fluoroalkyl; propenyl; C₃ -C₅-alkynyl; furanyl; furfuryl; or phenyl which is unsubstituted or mono-,di or tri-substituted by fluorine, chlorine, methyl, methoxy ortrifluoromethyl; or C₅ -C₆ -cycloalkyl which is unsubstituted ormonosubstituted by chlorine; R₃ is hydrogen; or C₁ -C₃ -alkyl; R₄ ishydrogen; C₁ -C₅ -alkyl; aphenyl radical which is unsubstituted or mono-or disubstituted by methyl, methoxy, fluorine, chlorine, bromine ornitro; or C₃ -C₆ -cycloalkyl; or R₃ and R₄ together with the nitrogenatom, are piperazinyl; pyrrolidinyl; or morpholinyl or piperidinyl whichis unsubstituted or mono- or disubstituted by methyl or ethyl; R₅ isbonded in the para-position relative to the carbimino group and ishydrogen; fluorine; chlorine; bromine; C₁ -C₄ -alkyl; dimethylamino;trifluoromethyl; phenylthio; nitro; iodine; cyano; methoxy; phenyl; oris phenoxy which is unsubstituted or substituted by the radicals R₈ andR₉ ; and R₆ and R₇ independently of one another are hydrogen; chlorine;fluorine; bromine; iodine; methyl; trifluoromethyl;2,2,2-trifluoroethoxy; nitro; difluoromethyl; or dimethylamino; and R₈and R₉ independently of one another are hydrogen; fluorine; chlorine;bromine; methyl; or trifluoromethoxy; and R₁₀ and R₁₁ independently ofone another are C₁ -C₄ -alkyl; and the salts of the compounds of theformula I with acids and bases are to be singled out.

Compounds of the formula I in which R₁ is OR₂ ; SR₂ ; O--CHR₁₀ R₂ ;N(R₃)(CHR₁₀ R₄); N(R₁₁)(CHR₁₀ R₄); or NR₃ R₄ ; R₂ is C₁ -C₆ -alkyl;2-[tri-(ethoxy)-silyl]ethyl; 2-[tri-(methoxy)silyl]ethyl,2-[(diethoxy)-(tert.-butoxy)-silyl]ethyl; 2-chlorphenyl; 2-bromophenyl;3-bromophenyl; 3,5-dichlorophenyl; 2,3,5-trichlorophenyl;4-fluorophenyl; 3,4-dimethylphenyl; 3,5-dimethylphenyl;2-dimethylamino-1-methylethyl; propenyl; C₃ -C₅ -alkynyl; cyclohexyl;4-chlorophenyl; p-tolyl; m-tolyl; benzyl; 4-chlorobenzyl; furfuryl;2,2,3,3,3-pentafluoropropyl; 2-methoxy-1-methylethyl or2,2,2-tri-fluoroethyl; R₃ is hydrogen; methyl; or ethyl; R₄ is hydrogen;C₂ -C₅ -alkyl; cyclopropyl or cyclohexyl; or R₃ and R₄, together withthe nitrogen atom, are 2,6-dimethylmorpholinyl or 3-ethylpiperidinyl; R₅is bonded in the para-position relative to the carbimino group and ishydrogen; fluorine; chlorine; bromine; iodine; methyl; trifluoromethyl;nitro; tert.-butyl; or methoxy; R₆ is hydrogen; chlorine; fluorine;2,2,2-trifluoroethoxy or iodine; and R₇ is hydrogen; R₈ is hydrogen; orchlorine; and R₉ is hydrogen; and R₁₀ and R₁₁ independently of oneanother are C₁ -C₄ -alkyl; are preferred.

Compounds of the formula I in which R₁ is SR₂ ; OR₂ ; or NR₃ R₄ ; R₂ isC₁ -C₆ -alkyl; phenyl; chlorophenyl; or tolyl; R₃ is hydrogen; and R₄ isC₁ -C₅ -alkyl; and R₅ is in the para-position relative to the carbiminogroup and is hydrogen; fluorine; chlorine; or bromine; and R₆ ishydrogen; fluorine; chlorine; or bromine; and R₇ is hydrogen; are alsopreferred.

On the basis of the good tolerance towards crop plants, the followinggroups of compounds of the formula I are to mentioned--observing thedefinition of each of the other substituents:

Group A

Compounds of the formula I in which R₁ is SR₂.

Group B

Compounds of the formula I in which R₁ is OR₂ or OCHR₁₀ R₂.

Group C

Compounds of the formula I in which R₁ is NR₃ R₄, N(R₃)(CHR₁₀ R₄) orN(R₁₁)(CHR₁₀ R₄).

The following compounds may be mentioned as typical representatives ofthe substance class according to the invention. They can be prepared byprocesses analogous to those described in European Patent EP-A No.175,651 and according to the examples given in EP-A No. 207,000 (themelting points, which are uncorrected, are given in [°C.]:

                                      TABLE 1                                     __________________________________________________________________________    Compounds of the formula                                                       ##STR3##                                     (I)                             Compound                                Physical                              No.   R.sub.5    R.sub.6                                                                            R.sub.7                                                                            R.sub.1      constants                             __________________________________________________________________________    1.001 4-Cl       2-Cl H    SCH.sub.3                                          1.002 4-Cl       2-Cl H    SCH.sub.2 H.sub.5                                  1.003 4-Cl       2-Cl H    SC.sub.3 H.sub.7 (n)                                                                       n.sub.D.sup.31 1.6229                 1.004 4-Cl       2-Cl H    SC.sub.3 H.sub.7 (i)                                                                       oil                                   1.005 4-Cl       2-Cl H    SC.sub.4 H.sub.9 (n)                               1.006 4-Cl       2-Cl H    SC.sub.4 H.sub.9 (s)                               1.007 4-Cl       2-Cl H    SC.sub.4 H.sub.9 (t)                                                                       M.p. 50-52                            1.008 4-Cl       2-Cl H    SCH.sub.2 CHCH.sub.2                                                                       n.sub.D.sup.31 1.6376                 1.009 4-Cl       2-Cl H    SCH.sub.2 C CH                                     1.010 4-Cl       2-Cl H                                                                                   ##STR4##                                          1.011 4-Cl       2-Cl H                                                                                   ##STR5##    n.sub.D.sup.50 1.6431                 1.012 4-Cl       2-Cl H                                                                                   ##STR6##                                          1.013 4-Cl       2-Cl H                                                                                   ##STR7##    oil                                   1.014 4-Cl       2-Cl H                                                                                   ##STR8##    n.sub.D.sup.50 1.6532                 1.015 4-Cl       2-Cl H                                                                                   ##STR9##                                          1.016 4-Cl       2-Cl H    OCH.sub.3                                          1.017 4-Cl       2-Cl H    OC.sub.2 H.sub.5                                   1.018 4-Cl       2-Cl H    OC.sub.3 H.sub.7 (i)                                                                       n.sub.D.sup.50 1.5655                 1.019 4-Cl       2-Cl H    OC.sub.4 H.sub.9 (n)                               1.020 4-Cl       2-Cl H    OC.sub.4 H.sub.9 (t)                                                                       n.sub.D.sup.50 1.5578                 1.021 4-Cl       2-Cl H    OCH.sub.2 CCH                                      1.022 4-Cl       2-Cl H                                                                                   ##STR10##                                         1.023 4-Cl       2-Cl H                                                                                   ##STR11##                                         1.024 4-Cl       2-Cl H                                                                                   ##STR12##   m.p. 104-110° C.               1.025 4-Cl       2-Cl H    NHC.sub.2 H.sub.5                                  1.026 4-Cl       2-Cl H    NHC.sub.3 H.sub.7 (n)                              1.027 4-Cl       2-Cl H    NHC.sub.4 H.sub.9 (n)                              1.028 4-Cl       2-Cl H                                                                                   ##STR13##   m.p. 147-149° C.               1.029 4-Cl       2-Cl H                                                                                   ##STR14##                                         1.030 4-Cl       2-Cl H                                                                                   ##STR15##                                         1.031 4-Cl       2-Cl H                                                                                   ##STR16##                                         1.032 4-Cl       2-Cl 6-Cl SC.sub.3 H.sub.7 (i)                               1.033 4-Br       2-Cl H    SC.sub.3 H.sub.7 (i)                               1.034 4-Br       2-Cl H    SC.sub.4 H.sub.9 (t)                               1.035 4-Br       2-Cl H    SCH.sub.2 CHCH.sub.2                               1.036 4-Br       2-Cl H                                                                                   ##STR17##                                         1.037 4-Br       2-Cl H                                                                                   ##STR18##                                         1.038 4-F        2-Cl H    SC.sub.4 H.sub.9 (t)                               1.039 4-F        2-Cl H    SC.sub.3 H.sub.7 (i)                               1.040 4-F        2-Cl H                                                                                   ##STR19##                                         1.041 4-F        2-Cl H                                                                                   ##STR20##                                         1.042 4-Br       2-Cl H                                                                                   ##STR21##                                         1.043 4-Cl       H    H    SC.sub.4 H.sub.9 (t)                               1.044 4-NO.sub.2 2-NO.sub.2                                                                         H    SC.sub.4 H.sub.9 (t)                               1.045 4-OCH.sub.3                                                                              2-OCH.sub.2                                                                        6-OCH.sub.3                                                                        SC.sub.4 H.sub.9 (t)                               1.046 4-Cl       3-Cl H    SC.sub.4 H.sub.9 (t)                               1.047                                                                                ##STR22## H    H    SC.sub.4 H.sub.9 (t)                               1.048                                                                                ##STR23## H    H    SC.sub.4 H.sub.9 (t)                               1.049 4-Cl       2-Cl H    OCH.sub.2 CF.sub.3                                                                         n.sub.D.sup.50 1.5482                 1.050 4-Cl       2-Cl H                                                                                   ##STR24##                                         1.051 4-Cl       2-Cl H                                                                                   ##STR25##                                         1.052 4-Cl       2-Cl H                                                                                   ##STR26##                                         1.053 4-Cl       2-Cl H                                                                                   ##STR27##                                         1.054 4-Cl       2-F  H    OCH(CH.sub.3).sub.2                                1.055 4-Cl       2-F  H    SC(CH.sub.3).sub.3                                 1.056 4-Cl       2-F  H                                                                                   ##STR28##                                         1.057 4-Cl       2-F  H    NHC(CH.sub.3).sub.3                                1.058 4-Cl       2-F  H    SCH(CH.sub.3).sub.2                                1.059 4-Cl       2-F  H                                                                                   ##STR29##                                         1.060 4-Cl       2-F  H                                                                                   ##STR30##                                         1.061 H          2-Cl H                                                                                   ##STR31##                                         1.062 H          2-Cl H    OCH(CH.sub.3).sub.2                                1.063 H          2-Cl H    SCH(CH.sub.3).sub.2                                1.064 H          2-Cl H    NHC(CH.sub.3).sub.3                                1.065 H          2-Cl H                                                                                   ##STR32##                                         1.066 H          2-F  H    OCH(CH.sub.3).sub.2                                1.067 H          2-F  H    SCH(CH.sub.3).sub.2                                1.068 H          2-F  H                                                                                   ##STR33##                                         1.069 H          2-F  H                                                                                   ##STR34##                                         1.070 4-CF.sub.3 H    H    OCH(CH.sub.3).sub.2                                1.071 4-CF.sub.3 H    H    SC(CH.sub.3).sub.3                                 1.072 H          3-CH.sub.3                                                                         2-CH.sub.3                                                                          ##STR35##                                         1.073 H          3-CH.sub.3                                                                         2-CH.sub.3                                                                         OCH(CH.sub.3).sub.2                                1.074 H          3-CH.sub.3                                                                         2-CH.sub.3                                                                         SCH(CH.sub.3).sub.2                                1.075 4-Cl       2-Cl H                                                                                   ##STR36##                                         1.076 4-Cl       2-Cl H                                                                                   ##STR37##                                         1.077 4-Cl       2-Cl H                                                                                   ##STR38##                                         1.078 4-Cl       2-F  H                                                                                   ##STR39##                                         1.079 4-Cl       2-F  H                                                                                   ##STR40##                                         1.080 4-Cl       2-F  H                                                                                   ##STR41##                                         1.081 4-Br       2-Cl H                                                                                   ##STR42##                                         1.082 4-Br       2-Cl H                                                                                   ##STR43##                                         1.083 4-Cl       H    H                                                                                   ##STR44##   m.p. 122-125°                  1.084 4-Cl       H    H    S C(CH.sub.3).sub.3                                                                        m.p. 77-101°                   1.085 4-Cl       H    H    OCH(CH.sub.3).sub.2                                                                        n.sub.D.sup.49 1.5693                 __________________________________________________________________________

                  TABLE 2                                                         ______________________________________                                        Compounds of the formula                                                       ##STR45##                     (I)                                            Compound                                  Physical                            No.     R.sub.6 R.sub.7                                                                             R.sub.8                                                                            R.sub.9                                                                           R.sub.1    constants                           ______________________________________                                        2.001   H       H     H    H   SC.sub.3 H.sub.7 (i)                           2.002   H       H     H    H   SC.sub.4 H.sub.9 (t)                           2.003   H       H     H    H                                                                                  ##STR46##                                     2.004   H       H     H    H                                                                                  ##STR47##                                     2.005   H       H     H    H   OC.sub.2 H.sub.5                               2.006   H       H     H    H                                                                                  ##STR48##                                     2.007   H       H     H    H   SCH.sub.2 CHCH.sub.2                           2.008   H       H     H    H                                                                                  ##STR49##                                     2.009   2-CH.sub.3                                                                            H     4-Cl H   SC.sub.3 H.sub.7 (i)                           2.010   2-CH.sub.3                                                                            H     4-Cl H   SC.sub.4 H.sub.9 (t)                           2.011   2-CH.sub.3                                                                            H     4-Cl H                                                                                  ##STR50##                                     2.012   2-CH.sub.3                                                                            H     4-Cl H   SCH.sub.2 CHCH.sub.2                           2.013   2-CH.sub.3                                                                            H     4-Cl H                                                                                  ##STR51##                                     2.014   2-CH.sub.3                                                                            H     4-Cl H                                                                                  ##STR52##                                     2.015   2-Cl    H     4-Cl H   SC.sub.3 H.sub.7 (i)                           2.016   2-Cl    H     4-Cl H   SC.sub.4 H.sub.9 (t)                           2.017   2-Cl    H     4-Cl H                                                                                  ##STR53##                                     2.018   2-Cl    H     H    H   SCH.sub.2 CHCH.sub.2                           2.019   2-Cl    H     H    H   OC.sub.2 H.sub.5                               2.020   2-Cl    H     H    H                                                                                  ##STR54##                                     2.021   2-Cl    H     H    H                                                                                  ##STR55##                                     2.022   2-Br    H     4-Br H   SC.sub.4 H.sub.9 (t)                           2.023   2-CH.sub.3                                                                            H     4-Br H   SC.sub.4 H.sub.9 (t)                           2.024   2-Cl    H     4-Br H   SC.sub.4 H.sub.9 (t)                           ______________________________________                                    

Analogously to the C═C double bond, the C═N double bond in the compoundsof the formula I leads to different geometric isomers:

Compounds of the formula I ##STR56##

A mixture of the syn and anti forms is in general formed in thepreparation of compounds of the formula I, the thermodynamically morefavorable form preferably being formed. The substances can be used inplant protection without resolution of the isomers. Nevertheless, theuse of the pure isomers may lead to a change in action.

The invention thus relates to all the isomeric compounds of the formulaI in the pure form or in any desired numerical ratio to one another.

The compounds according to formula I can be prepared by processesanalogous to the process known from European Patent No. A-175,651, byreacting a compound of the formula II with a compound of the formula III##STR57## in the presence of a base, HZ being split off. Z here is agroup which can be split off under the reaction conditions, such ashalogen, but can also be C₁ -C₄ -alkylthio or phenylthio, if R₁ H isOR₂, OCH₁₀ R₂, N(R₃)(CHR₁₀ R₄), N(R₁₁)(CHR₁₀ R₄) or NR₃ R₄, or can alsobe C₁ -C₄ -alkoxy or phenoxy if R₁ H is N(R₃)(CHR₁₀ R₄), N(R₁₁)(CHR₁₀R₄) or NR₃ R₄.

The reaction of (II) with (III) to give (I) is preferably carried outwith hydrogen halide being split off. Advantageous reaction temperaturesare between 0° and +180° C., preferably +20° and +150° C. or at theboiling point of the solvent or solvent mixture. The use of acid-bindingcompositions (bases) is in general advantageous. Possible acid-bindingcompositions are organic and inorganic bases, for example tertiaryamines, such as trialkylamines (trimethylamine, triethylamine,tripropylamine and the like), pyridines (4-dimethylaminopyridine,4-pyrrolidylaminopyridine and the like), alcoholates, for examplepotassium tert.-butylate, oxides and hydroxides, carbonates andbicarbonates of alkali metals and alkaline earth metals and the salts ofacetic acid, for example the alkali metal acetates.

One or more solvents or diluents which are inert in the reaction can onprinciple be present during the preparation of these products unlessexpressly specified in an individual case. Examples of suitable solventsor diluents are aliphatic and aromatic hydrocarbons, such as benzene,toluene, the xylenes and petroleum ether; halogenated hydrocarbons, suchas chlorobenzene, methylene chloride, ethylene chloride, chloroform,carbon tetrachloride and tetrachloroethylene; ethers and ether-likecompounds, such as dialkyl ethers (diethyl ether, diisopropyl ether,tert.-butylmethyl ether and the like), anisole, dioxane andtetrahydrofuran; nitriles, such as acetonitrile and propionitrile;N,N-dialkylated amides, such as dimethylformamide; dimethyl sulfoxide;ketones, such as acetone, diethyl ketone and methyl ethyl ketone, andmixtures of such solvents with one another.

The compounds of the formula III are generally known or can be preparedby methods which are known per se.

The compounds of the formula II are known from European Patent No.EP-A-175,651 and European Patent No. EP-A-0,207,000, or can be preparedby a procedure analogous to that described therein.

The invention furthermore relates to a process for the preparation ofcompounds of formula II ##STR58## wherein R₅, R₆, and R₇ are defined asgiven above and Z is halogen, in which process an amide of formula IV##STR59## wherein R₅, R₆ and R₇ are defined as above, is reacted with ahalogenating agent, such as SOCl₂, PBr₅, PCl₅, POCl₃, N-Bromosuccinimideetc., in a manner known in the art.

The amides of formula IV can be obtained by reacting acid halides offormula V ##STR60## wherein Hal is halogen and R₅, R₆ and R₇ are asdefined above, with 2-aminopyrazine VI ##STR61## in a manner well knownin the art.

The imides of formula II and the amides of formula VI are valuableintermediates for the synthesis of compounds of formula I and also anobject of this invention.

The invention further ore relates to herbicidal compositions containinga compound of the formula I and I' together with suitable auxiliariesand/or carriers.

The invention furthermore relates to methods of combating undesirableplant growth and to regulating plant growth using a herbicidal or plantgrowth-regulating amount of an active substance of the formula I.

As a rule, the active substances of the formula I are employedsuccessfully at application rates of 0.05 to 4 kg/ha, in particular 0.1to 1 kg/ha. The dosage required for the desired action can be determinedby experiments. It depends on the nature of the action, the developmentstage of the crop plant and of the weed and on the application(location, time and method), and as a result of these parameters canvary within wide limits.

At lower application rates, the compounds of the formula I aredistinguished by good selective growth inhibiting and selectiveherbicidal properties, which make them outstandingly suitable for use incrops of useful plants, especially in cereals, cotton, soybean, cornand, in particular, rice.

The compounds of the formula I also have powerful plantgrowth-regulating properties. The growth of both monocotyledons anddicotyledons is influenced.

In the case of many cultivated plants, an inhibition of vegetativegrowth permits denser planting of the crop, so that a higher yield maybe obtained per soil area.

A further mechanism through which yield is increased using growthregulators is based on the fact that a greater proportion of thenutrient goes to promoting flower and fruit formation, while vegetativegrowth is restricted.

At higher rates of application, weeds and grasses are so severelydamaged in their development that they die.

The invention also relates to herbicidal and plant growth-regulatingagents which contain an active substance of the formula I, and tomethods of combating weeds before and after emergence and forinfluencing the plant growth of monocotyledon and dicotyledon plants,especially grasses, tropical cover crops and side shoots.

The compounds of the formula I are used in unmodified form or preferablyas compositions together with the auxiliary agents which are usual informulation technology and are therefore processed, in a known way, togive e.g. emulsifiable concentrates, directly sprayable or dilutablesolutions, dilute emulsions, wettable powders, soluble powders, dustingagents, granulates and encapsulations in e.g. polymeric substances. Boththe nature of the compositions and the application methods, such asspraying, atomizing, dusting, scattering or watering, are selected inaccordance with the intended objectives and given circumstances.

The formulations, i.e. the agents, preparations or compositionscontaining the active substance of formula I and, where appropriate, asolid or liquid additive are prepared in known ways, e.g. by intimatelymixing and/or milling the active substances with extenders such as withsolvents, solid carriers and, where appropriate, surface-activecompounds (surfactants).

Solvents which may be used are: aromatic hydrocarbons, preferably C₈ toC₁₂ fractions, e.g. xylene mixtures or substituted naphthalenes,phthalates such as dibutyl or dioctyl phthalate, aliphatic hydrocarbonssuch as cyclohexane or paraffins, alcohols and glycols as well as theirethers and esters, such as ethanol, ethylene glycol, ethylene glycolmonomethyl or -ethyl ether, ketones such as cyclohexanone, stronglypolar solvents such as N-methyl-2-pyrrolidone, dimethyl sulfoxide ordimethylformamide, as well as nonepoxidized or epoxidized vegetable oilssuch as epoxidized coconut oil or soya oil; or water.

The solid carriers used, e.g. for dusting agents and dispersiblepowders, are, as a rule, natural rock flours such as calcite, talc,kaolin, montmorillonite or attapulgite. Highly disperse silica or highlydisperse absorbent polymers can also be added to improve the physicalproperties. Porous types such as e.g. pumice, crushed brick, sepioliteor bentonite, and nonsorptive carrier materials e.g. calcite or sand canbe used as particulate adsorptive granular carriers. In addition, alarge number of pregranulated substances of an inorganic or organicnature, such as especially dolomite or comminuted plant residues, can beused.

Depending on the nature of the active substance of formula I which is tobe formulated, nonionic, cationic and/or anionic surfactants having goodemulsifying, dispersing and wetting properties come into considerationas surface-active compounds. Surfactants are also to be understood toinclude surfactant mixtures.

Suitable anionic surfactants can be either so-called water-soluble soapsor water-soluble synthetic surface-active compounds.

Alkali metal, alkaline-earth metal, or optionally substituted ammoniumsalts of higher fatty acids (C₁₀ -C₂₂), such as e.g. the Na or K saltsof oleic or stearic acids, or of natural mixed fatty acids which may beobtained e.g. from coconut oil or tallow oil, may be mentioned as soaps.Fatty acid methyltaurate salts may also be mentioned, furthermore.

More frequently, however, so-called synthetic surfactants are used,especially fatty sulfonates, fatty sulfates, sulfonated benzimidazolederivatives or alkylarylsulfonates.

The fatty sulfonates or sulfates are usually present in the form ofalkali metal, alkaline-earth metal or optionally substituted ammoniumsalts and comprise an alkyl radical containing 8 to 22 C atoms, in whichalkyl also includes the alkyl moiety of acyl radicals, e.g. the Na or Casalt of ligninsulfonic acid, of dodecyl sulfate or of a fatty alcoholsulfate mixture prepared from natural fatty acids. The salts of sulfatesand sulfonic acids with fatty alcohol/ethylene oxide adducts are alsoincluded among these. The sulfonated benzimidazole derivativespreferably contain 2 sulfonic acid groups and a fatty acid radicalcontaining 8-22 C atoms. Alkylarylsulfonates are e.g. the Na, Ca ortriethanolamine salts of dodecylbenzenesulfonic acid, ofdibutylnaphthalenesulfonic acid or of a condensation product ofnaphthalenesulfonic acid with formaldehyde.

Furthermore, the corresponding phosphates, such as phosphoric acid estersalts of a p-nonylphenol-(4-14)/ethylene oxide adduct, or phospholipidsmay also be used.

Nonionic surfactants are principally polyglycol ether derivatives ofaliphatic or cycloaliphatic alcohols, saturated or unsaturated fattyacids and alkylphenols, which can contain from 3 to 10 glycol ethergroups and 8 to 20 carbon atoms in the (aliphatic) hydrocarbon radicaland 6 to 18 carbon atoms in the alkyl radical of the alkylphenols.

Further suitable nonionic surfactants are water-soluble adducts ofpolyethylene oxide with polypropylene glycol,ethylenediaminopolypropylene glycol and alkylpolypropylene glycol with 1to 10 carbon atoms in the alkyl chain, which contain 20 to 250 ethyleneglycol ether groups and 10 to 100 propylene glycol ether groups. Thesecompounds usually contain 1 to 5 ethylene glycol units per propyleneglycol unit.

As examples of nonionic surfactants there may be mentionednonylphenolpolyethoxyethanols, castor oil polyglycol ethers,polypropylene/polyethylene oxide adducts, tributylphenoxypolyethanol,polyethylene glycol and octylphenoxypolyethoxyethanol.

Fatty acid esters of polyoxyethylenesorbitan, such aspolyoxyethylenesorbitan trioleate are also suitable.

The cationic surfactants involved are principally quaternary ammoniumsalts whose N-substituents comprise at least one alkyl radicalcontaining 8 to 22 C atoms and which also have lower, halogenated orunhalogenated alkyl, benzyl or lower hydroxyalkyl radicals as furthersubstituents. The salts are preferably halides, methylsulfates orethylsulfates, e.g. stearyltrimethylammonium chloride orbenzyldi(2-chloroethyl)-ethylammonium bromide.

The surfactants customary formulation technology are described, interalia, in the following publications: "Mc Cutcheon's Detergents andEmulsifiers Annual", MC Publishing Corp., Ridgewood, N.J. 1979. "1985International Mc Cutcheon's Emulsifiers and Detergents", Glen Rock,N.J., U.S.A. Dr. Helmut Stache "Tensid Taschenbuch" Carl Hanser Verlag,Munich/Vienna 1981.

As a rule, the preparations contain 0.1 to 95%, in particular 0.1 to80%, of active substance of formula I, 1 to 99.9% of a solid or liquidadjuvant and 0 to 25%, in particular 0.1 to 25%, of a surfactant.

Formulations which are preferred consist, in particular, of thefollowing: (%=weight percentage)

    ______________________________________                                        Emulsifiable concentrates:                                                    active substance                                                                              1 to 20%, preferably 5 to 10%                                 of formula I:                                                                 surface-active agent:                                                                         5 to 30%, preferably 10 to 20%                                liquid carrier:                                                                              50 to 94%, preferably 70 to 85%.                               Dusts:                                                                        active substance of formula I:                                                                0.1 to 10%, preferably 0.1 to 1%                              solid carrier: 99.9 to 90%, preferably 99.9 to 99%.                           Suspension concentrates:                                                      active substance                                                                              5 to 75%, preferably 10 to 50%                                of formula I:                                                                 water:         94 to 25%, preferably 90 to 30%                                surface-active agent:                                                                         1 to 40%, preferably 2 to 30%.                                Wettable powders:                                                             active substance                                                                             0.5 to 90%, preferably 1 to 80%                                of formula I:                                                                 surface-active agent:                                                                        0.5 to 20%, preferably 1 to 15%                                solid carrier:   5 to 95%, preferably 15 to 90%.                              Granulates:                                                                   active substance of                                                                           0.5 to 30%, preferably 3 to 15%                               formula I:                                                                    solid carrier: 99.5 to 70%, preferably 97 to 85%.                             ______________________________________                                    

While concentrated compositions are preferred as commercial products, asa rule the end user uses dilute compositions. The application forms canbe diluted down to 0.001% of the active substance. As a rule the ratesof application are 0.005 to 5 kg a.s./ha.

The compositions can also contain further additives such as stabilizers,antifoams, viscosity regulators, binders, tackifiers, as well asfertilizers or other active substances aimed at producing specificeffects.

1. Preparation examples Example 1.1: Preparation of2-[2,4-dichlorobenzyl-C-(tert.-butylthio)imino]pyrazine ##STR62## a)Preparation of the intermediate N-(pyrazinyl)-2,4-dichlorobenziminechloride ##STR63##

16.6 g (0.062 mol) of the appropriate amide and 110 g (0.93 mol) ofthionyl chloride are stirred overnight at the boiling temperature, agentle stream of nitrogen being applied. The thionyl chloride was thenstripped off under reduced pressure, and the oil remaining was treatedtwice with toluene and each time evaporated thoroughly. The iminechloride is thus obtained virtually quantitatively as a brown oil.

(b) Preparation of the title compound

8.9 g (0.031 mol) of the imine chloride prepared and 3.6 g (0.04 mol) oftert-butyl mercaptan were introduced into 50 ml of tetrahydrofuran, and6.2 g (0.055 mol) of potassium tert-butylate in 50 ml of tetrahydrofuranwere added dropwise at 5° C. The reaction mixture was then stirred for 3hours at room temperature, poured into about 1 liter of ice watercontaining a little hydrochloric acid, and extracted twice with ethylacetate. The ethyl acetate solution was washed once with water, driedusing sodium sulfate, filtered and evaporated. The crude product waspurified via a silica gel flat column using ethyl acetate/petroleumether=1/3. 6.1 g of product were thus obtained.

The compounds of the formula I mentioned below can be obtainedanalogously to the procedures described.

                                      TABLE 1                                     __________________________________________________________________________    Compounds of the formula                                                       ##STR64##                                    (I')                            Compound                                 Physical                             No.   R.sub.5    R.sub.6                                                                            R.sub.7                                                                            R.sub.1      constants                             __________________________________________________________________________    1.001 4-Cl       2-Cl H    SCH.sub.3                                          1.002 4-Cl       2-Cl H    SCH.sub.2 H.sub.5                                  1.003 4-Cl       2-Cl H    SC.sub.3 H.sub.7 (n)                                                                       n.sub.D.sup.31 1.6229                 1.004 4-Cl       2-Cl H    SC.sub.3 H.sub.7 (i)                                                                       oil                                   1.005 4-Cl       2-Cl H    SC.sub.4 H.sub.9 (n)                               1.006 4-Cl       2-Cl H    SC.sub.4 H.sub.9 (s)                               1.007 4-Cl       2-Cl H    SC.sub.4 H.sub.9 (t)                                                                       m.p. 50-52° C.                 1.008 4-Cl       2-Cl H    SCH.sub.2 CHCH.sub.2                                                                       n.sub.D.sup.31 1.6376                 1.009 4-Cl       2-Cl H    SCH.sub.2 CCH                                      1.010 4-Cl       2-Cl H                                                                                   ##STR65##                                         1.011 4-Cl       2-Cl H                                                                                   ##STR66##   n.sub.D.sup.50 1.6431                 1.012 4-Cl       2-Cl H                                                                                   ##STR67##                                         1.013 4-Cl       2-Cl H                                                                                   ##STR68##   oil                                   1.014 4-Cl       2-Cl H                                                                                   ##STR69##   n.sub.D.sup.50 1.6532                 1.015 4-Cl       2-Cl H                                                                                   ##STR70##                                         1.016 4-Cl       2-Cl H    OCH.sub.3                                          1.017 4-Cl       2-Cl H    OC.sub.2 H.sub.5                                   1.018 4-Cl       2-Cl H    OC.sub.3 H.sub.7 (i)                                                                       n.sub.D.sup.50 1.5655                 1.019 4-Cl       2-Cl H    OC.sub.4 H.sub.9 (n)                               1.020 4-Cl       2-Cl H    OC.sub.4 H.sub.9 (t)                                                                       n.sub.D.sup.50 1.5578                 1.021 4-Cl       2-Cl H    OCH.sub.2 CCH                                      1.022 4-Cl       2-Cl H                                                                                   ##STR71##                                         1.023 4-Cl       2-Cl H                                                                                   ##STR72##                                         1.024 4-Cl       2-Cl H                                                                                   ##STR73##   m.p. 104-110° C.               1.025 4-Cl       2-Cl H    NHC.sub.2 H.sub.5                                  1.026 4-Cl       2-Cl H    NHC.sub.3 H.sub.7 (n)                              1.027 4-Cl       2-Cl H    NHC.sub.4 H.sub.9 (n)                              1.028 4-Cl       2-Cl H                                                                                   ##STR74##   m.p. 147-149° C.               1.029 4-Cl       2-Cl H                                                                                   ##STR75##                                         1.030 4-Cl       2-Cl H                                                                                   ##STR76##                                         1.031 4-Cl       2-Cl H                                                                                   ##STR77##                                         1.032 4-Br       2-Cl 6-Cl SC.sub.3 H.sub.7 (i)                               1.033 4-Br       2-Cl H    SC.sub.3 H.sub.7 (i)                               1.034 4-Br       2-Cl H    SC.sub.4 H.sub.9 (t)                               1.035 4-Br       2-Cl H    SCH.sub.2 CHCH.sub.2                               1.036 4-Br       2-Cl H                                                                                   ##STR78##                                         1.037 4-Br       2-Cl H                                                                                   ##STR79##                                         1.038 4-F        2-Cl H    SC.sub.4 H.sub.9 (t)                               1.039 4-F        2-Cl H    SC.sub.3 H.sub.7 (i)                               1.040 4-F        2-Cl H                                                                                   ##STR80##                                         1.041 4-F        2-Cl H                                                                                   ##STR81##                                         1.042 4-Br       2-Cl H                                                                                   ##STR82##                                         1.043 4-Cl       H    H    SC.sub.4 H.sub.9 (t)                               1.044 4-NO.sub.2 2-NO.sub.2                                                                         H    SC.sub.4 H.sub.9 (t)                               1.045 4-OCH.sub.3                                                                              2-OCH.sub.2                                                                        6-OCH.sub.3                                                                        SC.sub.4 H.sub.9 (t)                               1.046 4-Cl       3-Cl H    SC.sub.4 H.sub.9 (t)                               1.047                                                                                ##STR83## H    H    SC.sub.4 H.sub.9 (t)                               1.048                                                                                ##STR84## H    H    SC.sub.4 H.sub.9 (t)                               1.049 4-Cl       2-Cl H    OCH.sub.2 CF.sub.3                                                                         n.sub.D.sup.50 1.5482                 1.050 4-Cl       2-Cl H                                                                                   ##STR85##                                         1.051 4-Cl       2-Cl H                                                                                   ##STR86##                                         1.052 4-Cl       2-Cl H                                                                                   ##STR87##                                         1.053 4-Cl       2-Cl H                                                                                   ##STR88##                                         1.054 4-Cl       2-F  H    OCH(CH.sub.3).sub.2                                1.055 4-Cl       2-F  H    SC(CH.sub.3).sub.3                                 1.056 4-Cl       2-F  H                                                                                   ##STR89##                                         1.057 4-Cl       2-F  H    NHC(CH.sub.3).sub.3                                1.058 4-Cl       2-F  H    SCH(CH.sub.3).sub.2                                1.059 4-Cl       2-F  H                                                                                   ##STR90##                                         1.060 4-Cl       2-F  H                                                                                   ##STR91##                                         1.061 H          2-Cl H                                                                                   ##STR92##                                         1.062 H          2-Cl H    OCH(CH.sub.3).sub.2                                1.063 H          2-Cl H    SCH(CH.sub.3).sub.2                                1.064 H          2-Cl H    NHC(CH.sub.3).sub.3                                1.065 H          2-Cl H                                                                                   ##STR93##                                         1.066 H          2-F  H    OCH(CH.sub.3).sub.2                                1.067 H          2-F  H    SCH(CH.sub.3).sub.2                                1.068 H          2-F  H                                                                                   ##STR94##                                         1.069 H          2-F  H                                                                                   ##STR95##                                         1.070 4-CF.sub.3 H    H    OCH(CH.sub.3).sub.2                                1.071 4-CF.sub.3 H    H    SC(CH.sub.3).sub.3                                 1.072 H          3-CH.sub.3                                                                         2-CH.sub.3                                                                          ##STR96##                                         1.073 H          3-CH.sub.3                                                                         2-CH.sub.3                                                                         OCH(CH.sub.3).sub.2                                1.074 H          3-CH.sub.3                                                                         2-CH.sub.3                                                                         SCH(CH.sub.3).sub.2                                1.075 4-Cl       2-Cl H                                                                                   ##STR97##                                         1.076 4-Cl       2-Cl H                                                                                   ##STR98##                                         1.077 4-Cl       2-Cl H                                                                                   ##STR99##                                         1.078 4-Cl       2-F  H                                                                                   ##STR100##                                        1.079 4-Cl       2-F  H                                                                                   ##STR101##                                        1.080 4-Cl       2-F  H                                                                                   ##STR102##                                        1.081 4-Br       2-Cl H                                                                                   ##STR103##                                        1.082 4-Br       2-Cl H                                                                                   ##STR104##                                        1.083 4-Cl       H    H                                                                                   ##STR105##  m.p. 122-125°                  1.084 4-Cl       H    H    SC(CH.sub.3).sub.3                                                                         m.p. 97-101°                   1.085 4-Cl       H    H    OCH(CH.sub.3).sub.2                                                                        n.sub.D.sup.49 1.5693                 __________________________________________________________________________

                  TABLE 2                                                         ______________________________________                                        Compounds of the formula                                                       ##STR106##                    (I)                                            Compound                                  Physical                            No.     R.sub.6 R.sub.7                                                                             R.sub.8                                                                            R.sub.9                                                                           R.sub.1    constants                           ______________________________________                                        2.001   H       H     H    H   SC.sub.3 H.sub.7 (i)                           2.002   H       H     H    H   SC.sub.4 H.sub.9 (t)                           2.003   H       H     H    H                                                                                  ##STR107##                                    2.004   H       H     H    H                                                                                  ##STR108##                                    2.005   H       H     H    H   OC.sub.2 H.sub.5                               2.006   H       H     H    H                                                                                  ##STR109##                                    2.007   H       H     H    H   SCH.sub.2 CHCH.sub.2                           2.008   H       H     H    H                                                                                  ##STR110##                                    2.009   2-CH.sub.3                                                                            H     4-Cl H   SC.sub.3 H.sub.7 (i)                           2.010   2-CH.sub.3                                                                            H     4-Cl H   SC.sub.4 H.sub.9 (t)                           2.011   2-CH.sub.3                                                                            H     4-Cl H                                                                                  ##STR111##                                    2.012   2-CH.sub.3                                                                            H     4-Cl H   SCH.sub.2 CHCH.sub.2                           2.013   2-CH.sub.3                                                                            H     4-Cl H                                                                                  ##STR112##                                    2.014   2-CH.sub.3                                                                            H     4-Cl H                                                                                  ##STR113##                                    2.015   2-Cl    H     4-Cl H   SC.sub.3 H.sub.7 (i)                           2.016   2-Cl    H     4-Cl H   SC.sub.4 H.sub.9 (t)                           2.017   2-Cl    H     4-Cl H                                                                                  ##STR114##                                    2.018   2-Cl    H     H    H   SCH.sub.2 CHCH.sub.2                           2.019   2-Cl    H     H    H   OC.sub.2 H.sub.5                               2.020   2-Cl    H     H    H                                                                                  ##STR115##                                    2.021   2-Cl    H     H    H                                                                                  ##STR116##                                    2.022   2-Br    H     4-Br H   SC.sub.4 H.sub.9 (t)                           2.023   2-CH.sub.3                                                                            H     4-Br H   SC.sub.4 H.sub.9 (t)                           2.024   2-Cl    H     4-Br H   SC.sub.4 H.sub.9 (t)                           ______________________________________                                    

Biological examples Example B1: Pre-emergent herbicidal action

Immediately after the test plants have been sown in seed dishes in agreenhouse, the soil surface is treated with an aqueous spray liquorcorresponding to an application rate of 4 or 0.5 kg of activesubstance/hectare. The seed dishes are kept in a greenhouse at 22°-25°C. and 50-70% relative atmospheric humidity and the test is evaluatedafter 3 weeks.

In this test, the compounds of Tables 1 to 4 exhibit a potent herbicidalaction.

Specifically, the herbical action shown below is found at applicationrates of 4 kg/ha or 0.5 kg/ha against the weeds Echinochloa crus galliand Monocharia vag. which occur preferentially in corn, rice, soybean,cotton, sugarbeet and cereal crops.

The herbicidal action is evaluated according to a rating scale in which

1 is complete herbicidal action (plant has not germinated or has died)

2 to 8 are intermediate stages of decreasing action

9 is no action (as untreated control plant).

The ratings 2 to 4 can here be allocated to good herbicidal action andthe ratings 6 to 8 to tolerable damage (to the crop plants).

                  TABLE B                                                         ______________________________________                                        Application rate 4 kg/ha a.s.                                                 Compound No.                                                                              ECHINOCHLOA   MONOCHARIA                                          ______________________________________                                        1.003       1             1                                                   1.008       1             1                                                   1.024       1             1                                                   ______________________________________                                    

At an application rate of 500 g/ha a.s., the following values are foundfor Echinochloa crus galli, Scirpus spp., Monocharia vag. and riceplants.

                  TABLE B                                                         ______________________________________                                        Compound No.                                                                            Rice    Echinochloa                                                                              Scirpus                                                                              Monocharia                                ______________________________________                                        1.024     8       1          1      1                                         ______________________________________                                    

Example B2: Post-emergent herbicidal action (contact herbicide)

A number of weeds, both monocotyledons and dicotyledons, were sprayed onthe plants at the post-emergence stage (in the 4- to 6-leaf stage) withan aqueous dispersion of the active substance at a dose rate of 4 kg ofactive substance per hectare, and the plants were kept at 24°-26° C. and45-60% relative atmospheric humidity. 15 days after the treatment thetest is assessed. The compounds of Tables 1 and 2 show a good herbicidalaction in this test as well.

Example B3: Herbicidal action towards paddy rice

The water weeds Echinochloa crus galli and Monocharia vag. are sown inplastic beakers (surface area 60 cm², volume 500 ml). After sowing,these are filled with water to soil surface level. 3 days after sowing,the water level is increased to slightly above the soil surface (3-5mm). The application is carried out 3 days after sowing, by spraying thecontainers with the test substances. The dosage used corresponds to aquantity of active substance of 4 kg of a.s. per hectare. The plantbeakers are then kept in a greenhouse under optimum growth conditionsfor the rice weeds, i.e. at 25°-30° C. and at high atmospheric humidity.

Assessment of the tests takes place 3 weeks after application.

The compounds of Tables 1 and 2 damage the weeds here but not the rice.

Example B4: Growth inhibition of tropical leguminous cover crops

The test plants (Centrosema plumieri and Centrosema pubescens) arecultivated until fully grown and then cut back to a height of 60 cm.After 7 days the active substance is sprayed as an aqueous emulsion. Thetest plants are kept at 70% relative atmospheric humidity and 6000 luxartificial light for 14 hours per day at a temperature of 27° during theday and 21° C. at night. The test is assessed 4 weeks after theapplication. The new growth is then evaluated in comparison with thecontrol and is weighed and the phytotoxicity is assessed. In this test,the plants which have been treated with the active substances of Tables1 and 2 at rates of application of up to 3000 g/ha show a markedreduction in new growth (less than 20% of the new growth of untreatedcontrol plants), but without any damage being sustained by the testplants.

Example B5: Growth regulation in soybeans

Soybeans of the "Hark" variety are sown in plastic containers in anearth/peat/sand mixture in proportions of 6:3:1, and are placed in aclimatic chamber. Under optimum temperature control, illumination,fertilizer addition and watering conditions, the plants develop to the5-6 trefoil leaf stage after approximately 5 weeks. At this point intime the plants are sprayed with an aqueous liquor of an activesubstance of formula I until well wetted. The concentration of activesubstance is to up to 100 g a .s./ha. Assessment is carried outapproximately 5 weeks after the application of the active substance. Incomparison with untreated control plants, the active substances ofTables 1 and 2 according to the invention effect a marked increase inthe number and the weight of the husks on the leading shoot.

Example B6: Growth inhibition in cereals

The cereal varieties Hordeum vulgare (spring barley) and Secale (springrye) are sown in plastic pots with sterilized soil in a greenhouse andare watered as required. About 21 days after sowing the seedlings aresprayed with an aqueous spray liquor of an active substance of Tables 1and 2. The quantity of active substance is up to 100 g of activesubstance per hectare. 21 days after application the growth of thecereal is assessed. In comparison with the untreated controls, thetreated plants show a reduction in the new growth and, in some cases, anincrease in the diameter of the stalks.

Example B7: Growth inhibition in grasses

The grasses Lolium perenne, Poa pratensis, Festuca ovina, Dactylisglomerata and Cynodon dactylon are sown in a greenhouse in plasticdishes with a soil/peat/sand mixture (6:3:1) and are watered asrequired. The emerged grasses are cut back weekly to a height of 4 cmand, about 50 days after sowing and one day after the last cutting, aresprayed with an aqueous spray liquor of an active substance of Tables 1and 2. The amount of active substance, when converted, is up to 500 g ofactive substance per hectare. The growth of the grasses is assessed 21days after application.

In comparison to the untreated control, the tested compounds of Tables 1and 2 effect a reduction in the new growth.

Formulation examples Example F1: Formulation examples for activesubstances of formula I (%=weight percentage)

    ______________________________________                                        (a) Emulsifiable concentrates                                                                       (a)     (b)    (c)                                      ______________________________________                                        Active substance according to                                                                       20%     40%    50%                                      Table 1 or 2                                                                  Ca dodecylbenzenesulfonate                                                                           5%      8%    5.8%                                     Castor oil polyethylene glycol ether                                                                 5%     --     --                                       (36 mol EO)                                                                   Tributylphenol polyethylene glycol ether                                                            --      12%    4.2%                                     (30 mol EO)                                                                   Cyclohexanone         --      15%    20%                                      Xylene mixture        70%     25%    20%                                      ______________________________________                                    

Emulsions of any desired concentration may be prepared from suchconcentrates by dilution with water.

    ______________________________________                                        (b) Solutions       (a)     (b)     (c)                                       ______________________________________                                        Active substance according to                                                                     80%     10%     5%                                        Table 1 or 2                                                                  Ethylene glycol monomethyl ether                                                                  20%     --      --                                        Polyethylene glycol MW 400                                                                        --      70%     --                                        N--methyl-2-pyrrolidone                                                                           --      20%     5%                                        Epoxidized coconut oil                                                                            --      --      90%                                       ______________________________________                                    

The solutions are suitable for use in the form of tiny drops.

    ______________________________________                                        (c) Granules        (a)      (b)                                              ______________________________________                                        Active substance according to                                                                      5%      10%                                              Table 1 or 2                                                                  Kaolin              94%      --                                               Highly disperse silica                                                                             1%      --                                               Attapulgite         --       90%                                              ______________________________________                                    

The active substance is dissolved in methylene chloride, the solution issprayed onto the carrier and the solvent is then evaporated off invacuo.

    ______________________________________                                        (d) Dusts           (a)      (b)                                              ______________________________________                                        Active substance according to                                                                      2%      5%                                               Table 1 or 2                                                                  Highly disperse silica                                                                             1%      5%                                               Talc                97%      --                                               Kaolin              --       90%                                              ______________________________________                                    

A ready-to-use dust is obtained by mixing the carriers intimately withthe active substance.

    ______________________________________                                        (e) Wettable powders  (a)    (b)                                              ______________________________________                                        Active substance according to                                                                       20%    60%                                              Table 1 or 2                                                                  Na ligninsulfonate     5%    5%                                               Na laurylsulfate      --     6%                                               Octylphenol polyethylene glycol                                                                     --     2%                                               ether (7-8 mol EO)                                                            Highly disperse silica                                                                               5%    27%                                              Kaolin                70%    --                                               ______________________________________                                    

The active substance is mixed well with the additive and the mixture iswell ground in a suitable mill. Wettable powders are obtained, and thesecan be diluted with water to give a suspension of any desiredconcentration.

    ______________________________________                                        (f) Extruder granules                                                         ______________________________________                                        Active substance according to                                                                      10%                                                      Table 1 or 2                                                                  Na ligninsulfonate    2%                                                      Carboxymethylcellulose                                                                              1%                                                      Kaolin               87%                                                      ______________________________________                                    

The active substance is mixed with the additives and the mixture isground and moistened with water. This mixture is extruded and then driedin a stream of air.

    ______________________________________                                        (g) Coated granules                                                           ______________________________________                                        Active substance according to                                                                      3%                                                       Table 1 or 2                                                                  Polyethylene glycol (MW 200)                                                                       3%                                                       Kaolin               94%                                                      ______________________________________                                    

The finely ground active substance is applied uniformly in a mixer tothe kaolin which has been moistened with polyethylene glycol. Dust-freecoated granules are obtained in this manner.

    ______________________________________                                        (h) Suspension concentrate                                                    ______________________________________                                        Active substance according to Table 1 or 2                                                             40%                                                  Ethylene glycol          10%                                                  Nonylphenol polyethylene glycol ether                                                                   6%                                                  (15 mol EO)                                                                   Na ligninsulfonate       10%                                                  Carboxymethylcellulose    1%                                                  37% aqueous formaldehyde solution                                                                      0.2%                                                 Silicone oil in the form of a 75%                                                                      0.8%                                                 aqueous emulsion                                                              Water                    to 100%                                              ______________________________________                                    

The active substance is mixed intimately with the additives. Asuspension concentrate is obtained which can be used to preparesuspensions of any desired concentration by diluting with water.

What is claimed is:
 1. A compound of the formula I ##STR117## in whichR₁ is SR₂ ; OR₂ ; O--CHR₁₀ R₂ ; N(R₃)(CHR₁₀ R₄); N(R₁₁)(CHR₁₀ R₄); orNR₃ R₄ ; R₂ is C₁ -C₁₀ -alkyl which is unsubstituted or monosubstitutedby hydroxyl, mercapto, C₁ -C₄ -alkoxycarbonyl, mercapto-C₁ -C₄ -alkoxy,C₁ -C₄ -alkoxy, C₁ -C₄ -alkylcarbonyl, mono- or di-C₁ -C₄ -alkylamino,C₁ -C₄ -haloalkoxy, tri-(C₁ -C₄ -alkoxy)silyl, cyano, nitro or phenyl;C₁ -C₄ -haloalkyl; C₃ -C₈ -alkenyl; (3-methyloxetan-3-yl)methyl; C₃ -C₈-alkynyl; or a radical from the group consisting of phenyl, benzyl, C₃-C₇ -cycloalkyl, furanyl or furfuryl which is unsubstituted or mono-,di- or trisubstituted by identical or different substituents from thegroup consisting of halogen, C₁ -C₄ -alkyl; C₁ -C₄ -alkylcarbonyl,nitro, C₁ -C₄ -alkoxy and C₁ -C₄ -haloalkyl; R₃ and R₄ independently ofone another are hydrogen; a phenyl or benzyl radical which isunsubstituted or mono-, di-, tri- or tetra-substituted by identical ordifferent substituents from the group consisting of halogen, C₁ --C₄-alkyl, C₁ -C₄ -alkylcarbonyl, nitro, C₁ -C₄ -alkoxy, C₁ -C₄ -haloalkyl,C₁ -C₄ -alkylthio and C₁ -C₄ -haloalkylthio; C₁ -C₈ -alkyl; or C₃ -C₆-cycloalkyl; or R₃ and R₄, together with the nitrogen atom, ispyrrolidinyl or piperidinyl and is unsubstituted or mono- disubstitutedby C₁ -C₄ -alkyl; R₅ is hydrogen; halogen; C₁ -C.sub. 8 -alkyl; C₁ -C₄-alkoxy; C₁ -C₄ -haloalkyl; nitro, cyano; C₁ --C₄ -haloalkoxy;phenylthio; di-C₁ -C₄ -alkylamino; phenyl; or is phenoxy which isunsubstituted or substituted by the radicals R₈ and R₉ ; R₆, R₇, R₈ andR₉ independently of one another are hydrogen; halogen; C₁ -C₈ -alkyl; C₁-C₄ -haloalkyl; C₁ -C₄ -alkoxy; C₁ -C₄ -haloalkoxy; nitro; cyano; ordi-C₁ -C₄ -alkylamino; and R₁₀ and R₁₁ independently of one another areC₁ -C₄ -alkyl; or an agriculturally acceptable salt of a compound of theformula I with an acid or base.
 2. The compound of the formula I asclaimed in claim 1, in which R₁ is SR₂ ; OR₂ ; O--CHR₁₀ R₂ ; N(R₃)(CHR₁₀R₄); N(R₁₁)(CHR₁₀ R₄) or NR₃ R₄ ; R₂ is C₁ -C₆ -alkyl which isunsubstituted or monosubstituted by hydroxyl, mercapto, methoxycarbonyl,phenyl, di-C₁ -C₂ -alkylamino, cyano, nitro, C₁ -C₂ -alkoxy, acetyl ortri-(C₁ -C₄ -alkoxy)silyl; C₇ -C₁₀ -alkyl; 3-methyloxetan-3-yl)methyl;C₁ -C₃ -fluoroalkyl; propenyl; C₃ -C₅ -alkynyl; furanyl; furfuryl; orphenyl which is unsubstituted or substituted by fluorine, chlorine,methyl, methoxy or trifluoromethyl; or C₅ -C₆ -cycloalkyl which isunsubstituted or monosubstituted by chlorine; R₃ is hydrogen; or C₁ -C₃-alkyl; R₄ is hydrogen; C₁ -C₅ -alkyl; a phenyl radical which isunsubstituted or mono- or disubstituted by methyl, methoxy, fluorine,chlorine, bromine or nitro; or C₃ -C₆ -cycloalkyl; or R₃ and R₄,together with the nitrogen atom, are pyrrolidinyl or piperidinyl whichis unsubstituted or mono- or disubstituted by methyl or ethyl; R₅ isbonded in the para-position relative to the carbimino group and ishydrogen; fluorine; chlorine; bromine; C₁ -C₄ -alkyl; dimethylamino;trifluoromethyl; phenylthio; nitro; iodine; cyano; methoxy; phenyl; oris phenoxy which is unsubstituted or substituted by the radicals R₈ andR₉ ; and R₆ and R₇ independently of one another are hydrogen; chlorine;fluorine; bromine; iodine; methyl; trifluoromethyl;2,2,2-trifluoroethoxy; nitro; difluoromethyl; or dimethylamino; and R₈and R₉ independently of one another are hydrogen; fluorine; chlorine;bromine; methyl; or trifluoromethoxy; and R₁₀ and R₁₁ independently ofone another are C₁ -C₄ -alkyl.
 3. The compound of the formula I asclaimed in claim 1, in which R₁ is SR₂ ; OR₂ ; O--CHR₁₀ R₂ ; N(R₃)(CHR₁₀R₄); N(R₁₁)(CHR₁₀ R₄) or NR₃ R₄ ; R₂ is C₁ -C₆ -alkyl;2-[tri-(ethoxy)silyl]ethyl; 2-[tri-(methoxy)-silyl]ethyl,2-[(diethoxy)(tert.-butoxy)-silyl]ethyl; propenyl; C₃ -C₅ -alkynyl;cyclohexyl; 4-chlorophenyl; p-tolyl; m-tolyl; 2-chlorophenyl;2-bromophenyl; 3-bromophenyl; 3,5-dichlorophenyl; 2,3,5-trichlorophenyl;4-fluorophenyl; 3,4-dimethylphenyl; 3,5-dimethylphenyl;2-dimethylamino-1-methylethyl; benzyl, 4-chlorobenzyl; furfuryl;2,2,3,3,3-pentafluoropropyl; 2-methoxy-1-methylethyl or2,2,2-trifluoroethyl; R₃ is hydrogen; methyl; or ethyl; R₄ is hydrogen;C₂ -C₅ -alkyl; phenyl; cyclopropyl or cyclohexyl; or R₃ and R₄, togetherwith the nitrogen atom, is 3-ethylpiperidinyl; R₅ is bonded in thepara-position relative to the carbimino group and is hydrogen; fluorine;chlorine; bromine; iodine; methyl; trifluoromethyl; nitro; tert.-butyl;or methoxy; R₆ is hydrogen; chlorine; fluorine; 2,2,2-trifluoroethoxy oriodine; and R₇ is hydrogen; R₈ is hydrogen; or chlorine; and R₉ ishydrogen; and R₁₀ and R₁₁ independently of one another are C₁ -C₄-alkyl.
 4. The compound of the formula I as claimed in claim 1, in whichR₁ is SR₂ ; OR₂ ; or NR₃ R₄ ; R₂ is C₁ -C₆ -alkyl; phenyl; chlorophenyl;or tolyl; R₃ is hydrogen; and R₄ is C₁ -C₅ -alkyl; and R₅ is in thepara-position relative to the carbimino group and is hydrogen; fluorine;chlorine; or bromine; and R₆ is hydrogen; fluorine; chlorine; orbromine; and R₇ is hydrogen.
 5. The compound of the formula ##STR118##as claimed in claim
 1. 6. A plant growth-regulating compositioncontaining the compound as claimed in claim 1 in an amount effective asa plant growth regulator and an agriculturally acceptable carrier.
 7. Acomposition as claimed in claim 6 which is a herbicidal composition. 8.A method of regulating plant growth, which comprises allowing a plantgrowth-regulating amount of a compound of the formula I ##STR119## inwhich R₁ is SR₂ ; OR₂ ; O--CHR₁₀ R₂ ; N(R₃)(CHR₁₀ R₄); N(R₁₁)(CHR₁₀ R₄);or NR₃ R₄ ; R₂ is C₁ -C₁₀ -alkyl which is unsubstituted ormonosubstituted by hydroxyl, mercapto, C₁ -C₄ alkoxycarbonyl,mercapto-C₁ -C₄ -alkoxy, C₁ -C₄ -alkoxy, C₁ -C₄ -alkylcarbonyl, mono- ordi-C₁ -C₄ -alkylamino, C₁ -C₄ -haloalkoxy, tri-(C₁ -C₄ -alkoxy)silyl,cyano, nitro or phenyl; C₁ -C₄ -haloalkyl; C₃ -C₈ -alkenyl;(3-methyloxetan-3-yl)methyl; C₃ -C₈ -alkynyl; or a radical from thegroup consisting of phenyl, benzyl, C₃ -C₇ -cycloalkyl, furanyl orfurfuryl which is unsubstituted or mono-, di- or trisubstituted byidentical or different substituents from group consisting of halogen, C₁-C₄ -alkyl, C₁ -C₄ -alkylcarbonyl, nitro, C₁ -C₄ -alkoxy and C₁ -C₄-haloalkyl; R₃ and R₄ independently of one another are hydrogen; aphenyl or benzyl radical which is unsubstituted or mono-, di-, tri- ortetra-substituted by identical or different substituents from the groupconsisting of halogen, C₁ -C₄ -alkyl, C₁ -C₄ -alkylcarbonyl, nitro, C₁-C₄ -alkoxy, C₁ -C₄ -haloalkyl, C₁ -C₄ -alkylthio and C₁ -C₄-haloalkylthio; C₁ -C₈ -alkyl; or C₃ -C₆ -cycloalkyl; or R₃ and R₄together with the nitrogen atom, is pyrrolidinyl or piperidinyl and isunsubstituted or mono- disubstituted by C₁ -C₄ -alkyl; R₅ is hydrogen;halogen; C₁ -C₈ -alkyl; C₁ -C₄ -alkoxy; C₁ -C₄ -haloalkyl; nitro; cyano;C₁ -C₄ -haloalkoxy; phenylthio; di-C₁ -C₄ -alkylamino; phenyl; or isphenoxy which is unsubstituted or substituted by the radicals R₈ and R₉; R₆, R₇, R₈ and R₉ independently of one another are hydrogen; halogen;C₁ -C₈ -alkyl; C₁ -C₄ -haloalkyl; C₁ -C₄ -alkoxy; C₁ -C₄ -haloalkoxy;nitro; cyano; or di-C₁ --C₄ -alkylamino; and R₁₀ and R₁₁ independentlyof one another are C₁ -C₄ -alkyl; or an agriculturally acceptable saltof a compound of the formula I with an acid or base, to act on theplants or on the environment of the plants.
 9. A method as claimed inclaim 8 which is a method of combating undesirable plant growth, whereina herbicidal amount of the compound of the formula I is allowed to acton the plants or on the environment of the plants.
 10. The method asclaimed in claim 8, wherein a compound of the formula I in which R₁ isSR₂ ; OR₂ ; O--CHR₁₀ R₂ ; N(R₃)(CHR₁₀ R₄); N(R₁₁)(CHR₁₀ R₄) or NR₃ R₄ ;R₂ is C₁ -C₆ -alkyl which is unsubstituted or monosubstituted byhydroxyl, mercapto, methoxycarbonyl, phenyl, di-C₁ -C₂ -alkylamino,cyano, nitro, C₁ C₂ -alkoxy, acetyl or tri-(C₁ -C₄ -alkoxy)silyl; C₇-C₁₀ -alkyl; (3-methyl-oxetan-3-yl)methyl; C₁ -C₃ -fluoroalkyl;propenyl; C₃ -C₅ -alkynyl; furanyl; furfuryl; or phenyl which isunsubstituted or substituted by fluorine, chlorine, methyl, methoxy ortrifluoromethyl; or C₅ -C₆ -cycloalkyl which is unsubstituted ormonosubstituted by chlorine; R₃ is hydrogen; or C₁ -C₃ -alkyl; R₄ ishydrogen; C₁ -C₅ -alkyl; a phenyl radical which is unsubstituted ormono- or disubstituted by methyl, methoxy, fluorine, chlorine, bromineor nitro; or C₃ -C₆ -cycloalkyl; or R₃ and R₄, together with thenitrogen atom, are pyrrolidinyl; or piperidinyl which is unsubstitutedor mono- or disubstituted by methyl or ethyl; R₅ is bonded in thepara-position relative to the carbimino group and is hydrogen; fluorine;chlorine; bromine; C₁ -C₄ -alkyl; dimethylamino; trifluoromethyl;phenylthio; nitro; iodine; cyano; methoxy; phenyl; or is phenoxy whichis unsubstituted or substituted by the radicals R₈ and R₉ ; and R₆ andR₇ independently of one another are hydrogen; chlorine; fluorine;bromine; iodine; methyl; trifluoromethyl; 2,2,2-trifluoroethoxy; nitro;difluoromethyl; or dimethylamino; and R₈ and R₉ independently of oneanother are hydrogen; fluorine; chlorine; bromine; methyl; ortrifluoromethoxy; and R₁₀ and R₁₁ independently of one another are C₁-C₄ -alkyl; or a salt of a compound of the formula I with an acid orbase, is allowed to act as a herbicide or growth regulator on plants ortheir environment.
 11. The method as claimed in claim 8, wherein acompound of the formula I in which R₁ is SR₂ ; OR₂ ; O--CHR₁₀ R₂ ;N(R₃)(CHR₁₀ R₄); N(R₁₁)(CHR₁₀ R₄) or NR₃ R₄ ; R₂ is C₁ -C₆ -alkyl;2-[tri-(ethoxy)-silyl]ethyl; 2-[tri-(methoxy)-silyl]ethyl,2-[(diethoxy)-(tert.-butoxy)-silyl]ethyl; propenyl; C₃ -C₅ -alkynyl;cyclohexyl; 4-chlorophenyl; p-tolyl; m-tolyl; 2-chlorophenyl;2-bromophenyl; 3-bromophenyl; 3,5-dichlorophenyl; 2,3,5-trichlorophenyl;4-fluorophenyl; 3,4-dimethylphenyl; 3,5-dimethylphenyl;2-dimethylamino-1-methylethyl; benzyl; 4-chlorobenzyl; furfuryl;2,2,3,3,3-pentafluoropropyl; 2-methoxy-1-methylethyl or2,2,2-trifluoroethyl; R₃ is hydrogen; methyl; or ethyl; R₄ is hydrogen;C₂ -C₅ -alkyl; cyclopropyl or cyclohexyl; or R₃ and R₄, together withthe nitrogen atom is 3-ethylpiperidinyl; R₅ is bonded in thepara-position relative to the carbimino group and is hydrogen; fluorine,chlorine; bromine; iodine; methyl; trifluoromethyl; nitro, tert.butyl;or methoxy; R₆ is hydrogen; chlorine; fluorine; 2,2,2-trifluoroethoxy oriodine; and R₇ is hydrogen; R₈ is hydrogen; or chlorine; and R₉ ishydrogen; and R₁₀ and R₁₁ independently of one another are C₁ -C₄-alkyl; is allowed to act as a growth regulator on plants or theirenvironment.
 12. The method as claimed in claim 8, wherein a compound ofthe formula I in which R₁ is SR₂ ; OR₂ ; or NR₃ R₄ ; R₂ is C₁ -C₆-alkyl; phenyl; chlorophenyl; or tolyl; R₃ is hydrogen; and R₄ is C₁ -C₅-alkyl; and R₅ is in the para-position relative to the carbimino groupand is hydrogen; fluorine, chlorine; or bromine; and R₆ is hydrogen;fluorine; chlorine; or bromine; and R₇ is hydrogen; is allowed to act asa growth regulator on plants or their environment.
 13. The method asclaimed in claim 8, wherein a compound of the formula ##STR120## isallowed to act as a growth regulator on plants or their environment. 14.The method as claimed in claim 8, for combating undesirable plant growthin rice.